Power storage device

Abstract

A power storage device with high output is provided, in which the specific surface area is increased while keeping the easy-to-handle particle size of its active material. The power storage device includes a positive electrode including a positive electrode current collector and a positive electrode active material layer, a negative electrode including a negative electrode current collector and a negative electrode active material layer, and an electrolyte. The negative electrode active material layer includes a negative electrode active material having a plurality of graphite particles. Each of the graphite particles consists of graphite layers that are overlapped with each other with a gap of 1 nm to 10 nm therebetween. It is preferable that the grain diameter of the particle be 1 μm to 50 μm. Further, the specific surface area of the particles is 20 m 2 /g to 200 m 2 /g.

The invention claimed is: 
     
       1. An electrode comprising:
 a current collector; and 
 an active material layer, 
 wherein the active material layer comprises an active material exclusively of a plurality of graphite particles, 
 wherein each graphite particle of the plurality of graphite particles consists of a plurality of graphite layers overlapping with each other with a gap between each respective graphite layer, 
 wherein the gap is 1 nm to 10 nm, 
 wherein a grain diameter of the particle is 1 μm to 50 μm, and 
 wherein a specific surface area of the particle is 20 m 2 /g to 200 m 2 /g. 
 
     
     
       2. A power storage device comprising:
 a positive electrode comprising a positive electrode current collector and a positive electrode active material layer; 
 a negative electrode comprising a negative electrode current collector and a negative electrode active material layer; and 
 an electrolyte, 
 wherein the negative electrode active material layer comprises an active material exclusively of a plurality of graphite particles, 
 wherein each graphite particle of the plurality of graphite particles consists of a plurality of graphite layers overlapping with each other with a gap between each respective graphite layer, 
 wherein the gap is 1 nm to 10 nm 
 wherein a grain diameter of the particle is 1 μm to 50 μm, and 
 wherein a specific surface area of the particle is 20 m 2 /g to 200 m 2 /g. 
 
     
     
       3. The power storage device according to  claim 2 , wherein the electrolyte is in contact with the gap. 
     
     
       4. The power storage device according to  claim 2 , wherein the power storage device is a lithium ion capacitor. 
     
     
       5. The power storage device according to  claim 2 ,
 wherein the positive electrode active material layer comprises a graphite particle, and 
 wherein the graphite particle comprises a plurality of graphite layers overlapping with each other with a gap between each respective graphite layer. 
 
     
     
       6. A power storage device comprising:
 a positive electrode comprising a positive electrode current collector and a positive electrode active material layer; 
 a negative electrode comprising a negative electrode current collector and a negative electrode active material layer; and 
 an electrolyte, 
 wherein the positive electrode active material layer comprises an active material exclusively of a plurality of graphite particles, 
 wherein each graphite particle of the plurality of graphite particles consists of a plurality of graphite layers overlapping with each other with a gap between each respective graphite layer, 
 wherein the gap is 1 nm to 10 nm, 
 wherein a grain diameter of the particle is 1 μm to 50 μm, and 
 wherein a specific surface area of the particle is 20 m 2 /g to 200 m 2 /g. 
 
     
     
       7. The power storage device according to  claim 6 , wherein the electrolyte is in contact with the gap. 
     
     
       8. The power storage device according to  claim 6 , wherein the power storage device is a lithium ion capacitor. 
     
     
       9. The electrode according to  claim 1 , wherein the gap is formed using zinc chloride. 
     
     
       10. The electrode according to  claim 1 ,
 wherein the gap includes space, and 
 wherein a transition metal chloride is removed from the space. 
 
     
     
       11. The power storage device according to  claim 2 , wherein the gap is formed using zinc chloride. 
     
     
       12. The power storage device according to  claim 2 ,
 wherein the gap includes space, and 
 wherein a transition metal chloride is removed from the space. 
 
     
     
       13. The power storage device according to  claim 6 , wherein the gap is formed using zinc chloride. 
     
     
       14. The power storage device according to  claim 6 , wherein the gap includes space, and wherein a transition metal chloride is removed from the space.